Based on the metal organic chemical vapor deposition (MOCVD) technology, we designed a mid-wave infrared quantum cascade laser (QCL) with continuous-wave (CW) and watt-level output powers at room temperature. By optimizing MOCVD growth conditions, we obtained double-phonon resonance (DPR) materials with a high-quality interface and prepared a 4.6 μm QCL with a maximum CW output power of 1.21 W at room temperature. Furthermore, we specifically studied the performance of devices made of materials grown in 30-stage and 40-stage active regions and explored the effect of different active region stages on the device performance. Compared with that of the device in the 30-stage active region, the equivalent output power per unit area of the device in the 40-stage active region is not significantly improved. Instead, the 40-stage device performance drops rapidly as temperature increases, which can be attributed to outstanding heat accumulation and quality deterioration caused by thick epitaxial materials. Therefore, it is necessary to fully consider the balance among factors such as the number of active stages, heat accumulation, and material growth quality when the output power of QCL is improved by increasing the number of active region stages. MOCVD is a technology commonly used in the semiconductor material industry. This research is of great significance for promoting efficient production of QCL materials and expanding applications of QCL technologies in industries.